Protection of airships against fire



Feb. 16 1926.

F. L. M. BOOTHBY PROTECTION OF AIRSHIPS AGAINST FIRE Filed 2 1924 3 Sheets-Sheet 1 J/farny Feb. 16 1926. 1,573,762

F. L. M. BOOTHBY EROTECTION 0F AIRSHIPS AGAINST FIRE Filed Feb, 2, 1924 3 SheetsSheet 2 Feb. 16 192 1,573,762

F. L. M. BOOTHBY V PROTECTION OF AIRSHIPS AGAINST FIRE Filed Feb. 2 1924 3 Sheets-Sheet 5 Patented Feb. 16, 1926."

FREDERICK rinwrs MAITLANn'BooTHhY,

F TILFoRn'NEAR FARNHAM, ENGLAND:

' PROTECTION or A-msmr's AGAINST FIRE.

Application filed February 2,1924; Serial-No; 690,205.

Tooll whom it may concern) Be it. known that }I, FREDERICK, Lnwr's MarrLAnp Boo'rHBY, a British subject, re'sid 'This invention relates to Relatingv to the Protecof which the the protection of airships against fire andrthe ,means and methods whereby such'protection isefiected. According to this invention I enclose, preferably completely,,the.gas bags of an air-v ship, from the hull of which the cabin is. m

suspended, in an outer cover or covers,

order toprov de aclosed:v space around the gas bag or bags, which space I fill with gas,

I derived from the exhaust of thewengina, wlnchol'lers the advantage of maintauung,

the gas bags, in good (301K11- by its moisture,

climates,- It being well knowntion even in hot that where the gas-bags are made of more than one material-he. g., cotton and goldbeaters-skin shrinkage at different; rates and cracking of I one fabric-occurs when taken from a moist atmosphere to a dry one.

This cover is provided with suitable openings or connections for the admission and escape of the gas; while one or nore' conduits or trunks may be provided in the, gas bag or between the gas bagsand ex: tending through the outercover, preferably. at the top for the escape of hydrogen'gas V from the bag or bags. Valvesmay be'proof the gas bag or bags and closable openings may be provided for the insertion of the hand for the purpose of adjusting the valves. Y. Y 40 At the top of of the exhaust gas from the space between the gas bag and cover, and a lightly loaded valve maybe provided in this opening. it is desired that the valves and openings be placed :in the lower part of the airship for.-

cert-ain new and useful vided between the conduits and the 'interi or,

the airship cover a ,rela-- tivel 1 large opening 1s provided torvescape I ship through a suitable opening oriopenlngs. I

I first cool the gas, preferably by usingit first forcooking and heating purposes, ai'ter whiehit maybe passed through-a filteror scrubber 1 to remove dust and although this is not essentialan'd then adinit it to the space between thegas bag and the outer cover. Alternatively, or in conjunction with the-above,.the gas may be cooled by passing it between two thin metal plates, th e outer one forming part of the outer cover or plating oftheship and the innerone being lagged, if it is desiredato prevent the heat passing to the interior ;-Theexhaust pg aszbeing heavy will tend to accumulate in th-e'lower; portion of the piro-. tective space and the lairtherein will be gradually displaced and "escape-through. an opening or OpeningS "inithe top I of the airship, prov idedrfor thatpurpose,-.and preferably through valves, into'the usual gasbagt'runks. NVhen all the air has been t-hus driven out, (the gasbag orbags will be' Vsurrounded by a, layer: of .moist, exhaust In descending, should the airship descend at a greater rate than the exhaust gas can cope witlufand; the pressure between the outer cover 1 and gas bag fall sufiiciently, air will enterqthrough the opening atthe top, or alternatively, air can beadmitted the exhaust'gas,contained in thecover to hghtenltheairship, or for other purpose, a

valvefat thelower sideof the cover is jprovided so that the gas can escape or be driren out. I The fuel supply inlay be similarly protected by a cover containing "non-flammable gas,,or the fuelmay be carriedi'usidef the outerucover surrounding the gas bags.

' Theaocompanying diagrams show examples of the manner in which the invention is-applicable zto various types of airships. Fig.- l shows'inelea' a t-ion a typical form of rigid or semi-rigid airship having its keel built below the frameof its hull, and

Fig. 2 1s a cross-section thereof, on a of the gas bags A and the inner surface of the hull B constituting a chamber C completely surrounding the several gas bags A. This chamber C is utilized for enveloping the hydrogen gas bags with the moist exhaust gas from the engines D, conducted by conduits E, leading the gas along the keel B through cooking apparatus as well as heating apparatus, which may be arranged in the ear F, and thence to the chamber C.

Each of the gas bags A is provided with the usual pressure controlling valve A and a manoeuvering valve A The pressure controlling valves A of adjacent 'gas bags can be opened to communicate with trunks or ducts A arranged between them through which the released gases escape to the atmosphere. At their lower ends the ducts A are provided with sleeves A extend ing into the keel B thus providing means of access to the valves A for adjusting or operating purposes. The ma'noeuvering valves A are arranged in ducts A forming passages through the chamber C from the gas bags A to atmosphere.

The chamber C is in communication with the atmosphere by means of an outlet opening or openings 0 which may be provided with a spring controlled non-return valve, through which the air is expelled by the heavier than air non-flammable exhaust gas entering the chamber C, preferably near its bottom. A similar lightlyloaded nonreturn valve C is provided for admitting air to the chamber C, in the rigid type of airship, when, as for example in a quick descent of the airship, the pressure of the non-flammable exhaust gas in chamber 0 drops below atmospheric pressure. If the non-flammable exhaust gas employed is lighter than air, the said, air outlet C and inlet C will be arranged on the underside of the hull. I also prefer to lead t'l'ie exhaust gas into the trunks A in order that no explosive'mixture may be formed therein on the escape of hydrogen through the valves-A.

The examples illustrated in Figs. 8 and et and in Figs. 5 and 6 show the adaptation be ensured.

of the invention to airships of the semi-rigid and non-rigid type respectively, and the arrangements are substantially analogous to that shown in Figs. 1 and 2.- In semi-rigid airships, having regard to the collapsible nature of the hull cover, however, it is here necessary, in order to maintain this cover inflated at all times, that the pressure in the chamber C be higher than the atmospheric pressure. For this reason the air outlet C will always be provided with a spring loaded non-return valve, while it may not be ad visable to rely entirely upon an automatic air inletas' shown at C Figs. land 2 for the rigid type-under atmospheric pressure. The valve C is therefore replaced by an air pipe G, to which air under pressure may be supplied by the slip stream of the propellers, 01' by pumping, in any suitable manner.

Fig. 7 shows a device by means of which cooling of the non flammable exhaust gases prior to their entering the chamber C may This device consists in a broad shallow channel H, through which the gas is conducted, before entering the chamber C, and which is formed between two parallel metal plates M,.M arranged flush with and as part of the hull cover B, preferably alongside of the slip stream of the propellers, and extending fore and aft for a suitable distance. the water of condensation to be drawn off to any desired place, and the inner metal plate M may be lagged to prevent the interior of the chamberfrom becoming heated.

What I claim and desire to protect by Letters Patent is 1'. Means for protecting airships against fire comprising a plurality of gas-bags, an envelope surrounding the same, and means for introducing cooled but moist gas derived from the engine exhaust to said envelope.

2. Means for protecting airships against fire comprising a plurality of gas-bags, an envelope surrounding the same, valved trunks communicating with said gas-bags, and means for introducing cooled but moist gas derived from the engine exhaust to said envelope and said trunks.

8. Means for protecting airships against fire comprising a plurality of gas-bags, an envelope surrouiuling the same. means for introducing cooled but moist gas derived from the engine exhaust to said envelope, and means for introducing air to said envelope for the purpose described.

In testimony whereof I affix my sig nature.

FREDERICK L. M. BOOTHBY.

A drain cock N enables 

